Some standard content:
National Standard of the People's Republic of China
3~63kV AC high voltage load switches
AC high voltage switches for ratedvoltagesfrom3kVto63kv
Theme content and scope of application
GB3804—90||tt| |Replaces GB3804-88
This standard specifies the terminology, product classification, technical requirements, test methods, inspection rules, marking, packaging, transportation, storage and other requirements for AC high-voltage load switches (hereinafter referred to as load switches) . This standard applies to load switches and their operating mechanisms and auxiliary equipment for power distribution in indoor and outdoor three-phase AC power systems with a rated voltage of 3 to 63kV and a rated frequency of 50Hz. 2 Reference standards
GB763 Heat generation of AC high-voltage electrical appliances during long-term operation GB1984
GB1985
GB2706
GB3309
GB5273
GB7354| | tt | | GB7675 | Partial discharge measurement of terminal blocks of electrical appliances and bushings
Opening and closing capacitor bank test of AC high-voltage circuit breakers GB11022
3 terminology
3.1 Load switch
General purpose for high-voltage switchgear Technical conditions
Able to make, carry and break current under normal circuit conditions (also under specified overload operating conditions) and to carry current for a specified time under specified abnormal circuit conditions (such as short circuit) switchgear. 3.2 Universal load switch
A load switch capable of carrying out all closing and breaking operations in the power distribution system up to its rated breaking current in the positive band, as well as a load switch capable of carrying and closing short-circuit current.
3.3 Special load switch
A load switch with one or several types of general load switches, but not all functions. 3.4 Special purpose load switch
is suitable as a load switch in addition to the switching requirements specified for general load switches. For example: motor load switches, single and back-to-back capacitor bank load switches, frequently operated load switches, isolation load switches, etc. 3.5. Isolating load switch
A load switch that can meet the isolation requirements specified for the isolating switch in the open position. 3.6 Frequently operated load switch
State Bureau of Technical Supervision approved on 1991-11-06 for implementation on 1991-06-01
GB3804-90
The specified operating frequency can be opened and closed higher than the continuous supply and distribution A load switch for the required operating frequency in an electrical system. 3.7 Motor load switch
is a special-purpose load switch designated for switching motors under steady state and braking conditions. 3.8 Single capacitor bank load switch
A special purpose load switch designated for switching a single capacitor bank with a charging current up to its rated single capacitor bank breaking current.
3.9 Back-to-back capacitor bank load switch
Designated for breaking the capacitor bank charging current until equal to its rated back-to-back where one or more capacitor banks are connected to the busbar or power side of the load switch A special-purpose load switch with capacitor bank breaking current. Such load switches shall be capable of closing up to a corresponding inrush current equal to the closing inrush current of their rated capacitor bank. 3.10 Active load breaking current
The breaking current when breaking the active load circuit. This load can be represented by a resistor and reactor connected in parallel. 3.11 Closed-loop breaking current
Breaking closed-loop transmission lines, or transformers connected in parallel with one or several transformers (in this circuit, the circuits on both sides of the load switch are still energized after breaking, and there is a breaking current when the voltage is much lower than the system voltage). 3.12 Cable charging breaking current
The breaking current when breaking the cable circuit under no-load condition. 3.13 No-load transformer breaking current
The breaking current when breaking the no-load transformer circuit. 3.14 Breaking current of a single capacitor bank
Breaking current when breaking a single capacitor bank connected to the power supply (excluding other capacitor bank circuits adjacent to the broken capacitor bank.
3.15 Back-to-back capacitor bank breaking current
Breaking current when breaking the circuit of a capacitor bank connected to the power supply (including other capacitor banks adjacent to the broken capacitor bank)
3.16. The closing inrush current of the capacitor bank
is the high-frequency and high-amplitude current that occurs when the capacitor bank circuit is connected to the power supply when one or several adjacent capacitor banks are connected to the power supply side. |Note: The frequency and amplitude of the inrush current depend on the capacitance and inductance values ??between the capacitor banks. 4 Product Categories
Product varieties are listed in Table 1
Table 1
Classification. Method
Type
According to use
1. General load switch
2. Special load switch
3. Special purpose load
switch
5 Technical requirements
5.1 Environmental conditions
According to medium or
Extinguishing method
1.Air
2.SF||tt ||3.Vacuum
-4.Oil
According to the installation location
1.Outdoor
2.Indoor
According to the frequency of operation|| tt | Operating mechanism
1. Power
2. Human energy storage
According to the provisions of Chapter 3 of GB11022
5.2 rating
5.2.1 rating. Voltage
rated voltage is specified in Table 2
rated voltage
maximum voltage
3
3.5
6
GB3804—90
Table 2
10
6.9
Note: 1) The actual highest voltage in Northeast my country is 72.5kV. 11.5
35
40.5
63
691
kv
5.2.2 Rated current
Load switch rated current It is the maximum current value that can be broken under specified circuit conditions. The rated current is selected from the following values: 10, 16, 31.5, 50, 100, 200, 400, 630, 1250, 16005.2.3 Rated frequency
The rated frequency is 50Hz.
5.2.4 Rated insulation level
According to Article 5.4 of GB11022.
5.2.5 Rated short-time withstand current (rated thermal stability current) is in accordance with Article 5.5 of GB11022.
5.2.6 Rated short-circuit duration (rated thermal stability time) is in accordance with Article 5.6 of GB11022.
5.2.7 Rated peak withstand current (rated dynamic stability current) is in accordance with Article 5.7 of GB11022.
5.2.8 Rated parameter coordination
The rated parameter coordination of the universal load switch is preferably selected according to Table 3. Other rated parameter coordination can also be used. Table 3
rated voltage
kv
3,6
10
rated short-time withstand current
kA (effective value)
1.6
3.15
8
12.5
16
25
3.15
8|| tt||12.5
16
25
100
100
amount
200
200||tt| |Determined
Electricity
400
Flow, A
630
1250
630
1250||tt| |Rated voltage
kv
35
63
Rated short-time withstand current
kA (effective value)
3.15|| tt||8
12.5
16
25
8
12.5
16
25||tt| |31.5
GB3804—90
Continuation Table 3
amount
100
200
200
determined||tt ||Note: 1) Parameters for rated current greater than 1250A are to be determined (or negotiated between the user and the manufacturer). 5.2.9 The rated voltage of the closing and opening mechanisms and the auxiliary circuit power supply shall be in accordance with Article 5.8 of GB11022.
5.2.10 The rated pressure of the compressed air source for operation shall be in accordance with Article 5.9 of GB11022.
5.2.11 Terminal block rated static tension
electricity
400
flow, A
630
630
1250
12501)
For load switches that are required to withstand significant terminal static tension, the terminal static tension shall be in accordance with Article 4.13 of GB1985. For load switches that do not bear significant terminal static tension, there is no need to specify the terminal static tension. 5.2.12 Breaking current rating of universal load switch The universal load switch is characterized by the following rated breaking value: rated closed-loop breaking current is equal to the rated current; b.
c.
rated active power The load breaking current is equal to the rated current; the rated cable charging breaking current is 10A for 3~35kV level and 25A for 63kV. The manufacturer can choose a higher value according to the R10 series;
d.||tt| |The rated no-load transformer breaking current is the rated capacity of 1250kVA for 3~35kV grade, and 63kV is the no-load current of the distribution transformer with rated capacity of 5600kVA. The rated breaking current is based on:
at
voltage;
b.
Except that the recovery voltage of the rated closed-loop breaking current is equal to 20% of the maximum voltage, the given The power frequency recovery voltage is equal to the rated power. In the case of short circuit, in addition to the recovery voltage of the rated closed-loop breaking current using the specified values ??in Table 4 and Figure 1, the expected transient recovery voltage of the power circuit under short circuit conditions is equal to the rated value in GB1984. Rated instantaneous recovery voltage value when the specified outlet terminal fails.
Table 4
Rated voltage U
kv
3
6
10
35
63
Note: The first opening phase coefficient is 1.5.
Transient recovery voltage (peak value) ue
kv
1.2
2.4
4.0
14.0
19.0| |tt||Time coordinate ts
HS
109
104
148
330
350
Voltage rise Rate ue/ts
V/us
11
23
27
42
54
Voltage|| tt||GB3804—90
t,
Time
Figure 1 Transient recovery voltage of breaking closed-loop current test 5.2.13 Rating of special load switch
Special-purpose load switches have specific ratings, which should preferably be the same as those used for general-purpose load switches. If other ratings are specified, they should be selected from the R10 series.
5.2.14 Ratings of special-purpose load switches Special-purpose load switches are not required to have matching ratings. But the rated value should be selected from the R10 series. 5.2.15 Motor load switch rating
a. The rated breaking current under normal operating conditions is equal to the rated current. The power frequency recovery voltage is equal to 20% of the rated voltage. b. Unless otherwise specified, the rated breaking current under motor braking is 8 times the rated current. The power frequency recovery voltage is equal to the highest voltage.
5.2.16 Rated breaking current of a single capacitor bank The rated breaking current of a single capacitor bank is equal to 0.8 times the rated current of the load switch. Note: The coefficient 0.8 takes into account the harmonic components of the capacitor bank current. 5.2.17 Rated back-to-back capacitor bank breaking current Rated back-to-back capacitor bank breaking current is a situation where one or more capacitor banks are connected to the power supply side of the load switch close to the broken capacitor bank, resulting in a rated capacitor bank closing inrush current. , the load switch should be able to break the maximum capacitor bank breaking current at its highest voltage.
5.2.18 Rated capacitor bank closing inrush current
The rated capacitor bank closing inrush current is the current peak value that the load switch should be able to close at its highest voltage and the inrush frequency suitable for the working conditions. .
For load switches with rated back-to-back capacitor bank breaking current, the requirement of rated capacitor bank closing inrush current is mandatory. Note: The inrush rate of the back-to-back capacitor bank is determined by the equivalent series capacitance and inductance values ??of the circuit that generates the inrush current. When the capacitor bank is equipped with a current-limiting inductor of 6% to 11%, the inrush frequency is 150-200Hz. When there is no current-limiting inductor, the inrush frequency may be in the range of 2~30kHz. When a large-capacity back-to-back capacitor bank with series inductance is used, the inrush peak value may reach the rated short-circuit closing current value, or even exceed the electrodynamic force generated by the inrush current and the impact of the closing process, which may cause serious situations, especially for oil-type capacitors. load switch. 5.2.19 Rated short-circuit making current
Various load switches should have a rated short-circuit making current equal to their rated peak withstand current. Note: Short-circuit current rating for load switches followed by current-limiting fuses. The selection is based on the limiting effect of the combination fuse with the highest rated current on the value and duration of the short-circuit current. 5.3 Design and structure
5.3.1 The requirements for liquid and gas media in the load switch shall be in accordance with Articles 6.1 and 6.2 of GB11022,
5.3.2 Terminals of the load switch
The regulations of GB5273.
5.3.3 Grounding of load switch
According to Article 6.3 of GB11022
5.3.4 Auxiliary equipment of load switchwwW.bzxz.Net
According to Article 6.6 of GB11022||tt ||5.3.5 Closing operation of load switch
5.3.5.1 Power closing
According to the provisions of GB11022 Article 6.8.1.
5.3.5.2 Can be closed
According to the provisions of GB11022 Article 6.8.2.
5.3.6 Release operation
According to GB11022 Article 6.9.
5.3.7 Low-pressure and high-pressure locking devices
According to GB11022 Article 6.10.
GB3804-90
5.3.8 The position of the moving contact system and its indication or signaling device 5.3.8.1 Positioning requirements
The load switch and its operating mechanism should be designed in this way, that is Forces or electromagnetic forces caused by gravity, vibration, moderate impact or accidental contact with the linkage of its operating mechanism cannot make it leave the opening or closing position. The load switch or its operating mechanism should be designed to allow measures to be taken. to prevent misuse. 5.3.8.2 Position indication
The position indication should be able to identify the opening and closing positions of the load switch. If one of the following conditions is met, the requirements are considered to be met: a: The air gap of the load switch is visible, and the isolation fracture of the isolating load switch is visible. b. The position of each moving contact is indicated by a reliable indicating device. Note: ① Visible moving contacts can be used as indicating devices. ② When all the poles of a load switch are connected together as a whole, a common indicating device is allowed to be used. 5.3.8.3 Auxiliary contacts for signals
The movable contacts can indeed fully carry the rated current , peak withstand and short-time withstand current positions, the closing position signal should not be sent out.
When the position of the movable contact has not reached such that the gap or isolation fracture is at least 80% of the total gap or total fracture distance, or when the position of the complete opening is not reached, the opening position signal should not be sent. 5.3.9 Nameplate
According to the requirements of Table 5.
Item
Manufacturer
Model
No.
Serial number
Rated voltage
Rated current
Rated frequency
Item
Rated lightning impulse withstand voltage
Rated short-time withstand current
Rated short-circuit duration
Number of operations under active load conditions
Rated cable charging breaking current
Rated breaking current under motor braking conditions (only for motor load switches)
Rated short-circuit making current
Rated sulfur hexafluoride gas pressure
Total number of load switches Weight
Factory No.
Year and Month of Manufacturing
Unit
GB3804—90
Table 5
position
kv
A
kv
kA
s
A
kA
MPa
kg
Load switch
x
(x)
x
(x)
x
+
x
Note: The mark of X is mandatory; the mark of (X) is optional; the mark of Y is subject to the last column of Table 5. 5.3.10 Requirements for synchronism of each phase
Indicate when necessary
When different from 20
When 3~35kV is higher than 10A
When 63kV is higher than 25A
When different from 8 times
rated current
The phase-to-phase synchronism of the three-phase load switch operated simultaneously by the power or energy operating mechanism should not be greater than 5ms, and the phase-to-phase synchronism of the closing mechanism should not be greater than 10ms.
5.3.11 Discharge hole
The setting of the discharge hole of the load switch should ensure that the discharge will not cause electrical breakdown, and the discharge direction should not endanger the safety of people and electrical equipment. 5.3.12 The size requirements for the operating parts of the human energy storage mechanism shall comply with Article 5.18 of GB1985.
5.3.13 Requirements for power operating mechanism
According to Article 5.19 of GB1985.
5.3.14 The direction of movement of the operating tool for the operating mechanism shall be in accordance with Article 6.11 of GB11022.
5.3.15 Requirements for isolating load switches
Should meet Article 5.4 of GB11022.
5.3.16 Interchangeability
The installation dimensions of load switches and their operating mechanisms of the same model shall be unified, and the same components, wearing parts and spare parts shall be interchangeable.
5.3.17
Sealing of load switches
The sealing performance of liquid and gas medium load switches shall be specified in the product technical conditions. 5.3.18 Rain protection of load switch
GB3804-90
When outdoor load switch and operating mechanism with housing are exposed to rain, there should be no trace of water ingress inside the housing, and the insulation performance should not be reduced. 5.3.19 Ice breaking of load switch
The ice breaking thickness of outdoor load switch should be specified in the product technical conditions. 6 Test content and method
6.1 Temperature rise test
Carry out in accordance with the provisions of GB763.
6.2 Insulation test
Carry out in accordance with Article 7.1 of GB11022.
6.3 Main circuit resistance measurement
Carry out in accordance with the provisions of GB763.
6.4 Short-time withstand current and peak withstand current tests shall be carried out in accordance with the provisions of GB2706.
6.5 Closing and breaking tests
6.5.1 Arrangement of the load switch under test
The load switch under test shall be completely mounted on its own support. Its operating mechanism shall be operated in the prescribed manner. In particular, if the operating mechanism is electric or pneumatic, its operation shall be carried out at the lowest voltage or lowest air pressure respectively, unless the interruption of the current may affect the test results. In the latter case, the voltage or air pressure at which the load switch is operated shall be selected within the prescribed range so that the highest speed and maximum arc-extinguishing performance are achieved when the contacts are separated. It should be shown that the load switch can operate satisfactorily under the above conditions when it is unloaded. If possible, data such as the travel of the moving contacts should be recorded. Non-manually operated load switches can be operated by remote control closing devices. 6.5.1.1 Due consideration should be given to the selection of the live side connection. When the load switch is intended to be connected to the power supply from both sides and the actual arrangement on one side of the load switch is different from that on the other side, the power supply of the test circuit should be connected to the side that reflects the heaviest working conditions of the load switch. If in doubt, part of the operation shall be carried out with the power connected to one side of the load switch and part of the operation shall be carried out with the power connected to the other side of the load switch.
6.5.1.2 Closing and breaking tests of three-pole load switches with all poles operated simultaneously shall be carried out on three phases unless otherwise specified. Closing and breaking tests of three-pole switches (composed of three single-pole load switches) operated pole by pole shall be carried out on single phase, except for capacitive load breaking tests with special requirements. 6.5.1.3 Except for load switches filled with liquid or gas and vacuum load switches, if there is significant flame or metal particle splashing, it may be required to place metal screens near live parts and leave them a safe clearance distance specified by the manufacturer during the test. Metal screens, brackets and other normally grounded parts shall be insulated from the ground and connected to a suitable grounding device after being connected to each other to indicate whether there is significant leakage current to the ground.
6.5.2 Earthing of the test circuit
The load switch (whose bracket should be earthed as in operation) shall be connected to the three-phase test circuit with the neutral point of the source or the neutral point of the load earthed. In the first case, the zero-sequence impedance shall be less than three times the positive-sequence impedance on the source side. The connection method used shall be noted in the test report. 6.5.2.1 Earthing of the blue-phase test circuit for the cable charging current interruption test For load switches used in neutral point insulation and resonant earthing systems, the neutral point on the source side shall be insulated or earthed through an arc suppression coil.
6.5.2.2 The test circuit and the bracket of the single-pole switch shall be earthed so that the voltage conditions between the live parts in the switch and the ground are the same as in operation after the arc is extinguished. The connection method used shall be noted in the test report. 6.5.3 Test procedure for load switches
6.5.3.1 Test procedure for general load switches The test method and test procedure for three-phase switches shall be as specified in Table 6. Test method
and procedure
1
2
3
4
5
Content
GB3804—90
Table 6 Test method and procedure for general load switch Content
“Close-open” rated active load breaking current “Close-open” closed-loop breaking current
“Close-open\5% rated active load breaking current “Close-open” rated cable charging current||t t||Closing rated short-circuit closing current
Test voltage
U.
0.2Um
Um
Test current
0.051
I
4
Note: ①Um, I, I are the maximum voltage, rated current and rated short-circuit closing current of the load switch respectively. ②I. For 3~35kV, it is 10A, for 63kV, it is 25A. Test
Number of times| |tt||General type
10
20
10
2
The single-phase test procedure for phase-by-phase operation of universal load switches (composed of three single-pole load switches) shall be as specified in Table 7. Table 7 Single-phase test method and procedure for phase-by-phase operation of universal load switches Test method
and procedure
1a
1b
2a
2b
3a
36| |tt||4a
4b
4c
5
Content
Test voltage
F1.5Um/V3
“Close-open” rated active load breaking
current
“Close-open” closed-loop breaking current
Um
1.5×0.2
Um/V3
0.2Um
1.50m/V3 | | tt | ||Rated short-circuit closing current
Note: ①Um, I, L have the same meaning as Table 6
Um
U
U.
U/V3
Um
Test current
1
0.871
0.871
0.051
0.87×0.051|| tt||Te
0.871.
le
0.871
Number of tests
General type
5
Frequent type
50
10
10
20
2
say
frequent
100| |tt||10
20
2
Ming
indicates the prime minister breaking condition
indicates the second phase breaking condition
Indicates the prime breaking condition
Indicates the second phase breaking condition
Indicates the prime breaking condition
Indicates the second phase breaking condition
Load switch for common applications| |tt||Using three-phase test circuit
4a represents the primary breaking condition
4b represents the second phase breaking condition
4c is used for center point grounding system
And the load
switch with shielded cable adopts single-phase test circuit
to indicate the second phase compliance condition
②1. For 3~35kV, it is 25A. The test methods shall be carried out in sequence according to the given procedure without refurbishment of the load switch. However, test method 5 is an exception if it is obvious or can be proved that the closing ability is not affected by test methods 1 to 4. For the convenience of testing, the test shall be carried out. Mode 5 can be performed on another new load switch of the same model and parameters, unless limited by the design of the load switch itself. In the closing-opening operation, the opening operation should follow the closing operation, and in order to reduce the transient current. There should be sufficient artificial delay between these two operations. When the characteristics of the load switch design or the equipment conditions of the test station require it, the closing and opening operations can also be performed separately. The time interval between closing and opening operations should usually not exceed 3 minutes. In test mode 1, the impedance value of the power loop can rise to approximately the total impedance value of the test loop. 20%, and the number of operations reaches 20, test mode 2 will no longer be performed at this time
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